Greenstone Professional (GSPro) is a simulation software developed by Honeywell. It works with a variety of simulators, including Honeywell’s Experion PKS, TDC 3000, and C300 platforms. GSPro can also be integrated with other third-party simulators, such as SimSci-Esscor’s PRO/II and AspenTech’s Aspen HYSYS, through its OLE (Object Linking and Embedding) interface.